from a c++ program i need to print a simple label. the label contains a text, an image and a barcode.(in my project the label is more complex, this is just for example)
my customer need a way to customize che label layout.
in the past in java I solve this problem using a report created with jasperreport. my customer customize the report with ireport and then i fill the data with an hashtable datasource (i never connect to an sql database)
anybody know a way to obtain something like this in java
really sorry for my scholastic english
Offhand, it's a bit hard to say -- most report generators assume some sort of database (SQL or at least accessible via ODBC) as the data source. I'd probably look into some that are free and include source code so you can change the data source (though I've no idea how difficult a modification that will be).
The other problem is that printing anything but plain text is somewhat non-portable; you'll need different code for Linux, Mac/OS or Windows. For Windows, one possibility would be Report Generator from CodeProject.com. If you want something more portable, you could use something like Xport to create XHTML output to be viewed in/printed from a browser (or any number of other programs that understand [X]HTML (there's also a commercial version). Of course, you could generate output in any number of other formats that support graphics, such as Postscript/PDF, LaTex, etc. This lets you use portable code to generate the report, but usually requires some non-portable code to invoke a viewer.
Related
I am currently developping a windows application who test railroad equipments to find any defaults.
Utility A => OK
Utility B => NOK
...
This application will check the given equipment and generate a report.
This report needs to be written once, and no further modifications are allowed since this file can be used as working proof for the equipment.
My first idea was ta use pdf files (haru lib looks great), but pdf can also be modified.
I told myself that I could obsfuscate the report, and implement a homemade reader inside my application, but whatever way I store it, the file would always be possibly accessed and modified right?
So I'm running out of ideas.
Sorry if my approach and my problem appear naive but it's an intership.
Thanks for any help.
Edit: I could also add checksums for files after I generated them, and keep a "checksums record file", and implement a checksums comparison tool for verification? just thought about this.
I believe the answer to your question is to use any format whatosever, and use a digital signature anybody can verify, e.g., create a gnupg, get that key signed by the people who require to check your documents, upload it to one of the key servers, and use it to sign the documents. You can publish the documents, and have a link to your public key available for verification; for critical cases someone verifying must be trust your signature (i.e., trust somebody who signed your key).
People's lives depend on the state of train inspections. Therefore, I find it hard to believe that someone expects you to solve this problem only using free-as-in-beer components.
Adobe supports a strong digital signature model. If you buy into their technology base, you can create PDF's that are digitally signed, and are therefore tamper-evident, as the consumer can check for the signature.
You can, as someone else pointed out, use GNUpg, or for that matter OpenSSL, to implement your own signature scheme, but railroad regulators are somewhat less likely to figure out how to work with it.
I would store reports in an encrypted/protected datastore.
When a user accesses a report (requests a copy, the original is of course always in the database and cannot be modified), it includes the text "Report #XXXXX". If you want to validate the report, retrive a new copy from the system using the Report ID.
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I am starting work on a new piece of software that will end up needing some robust and expandable file IO. There are a lot of formats out there. XML, JSON, INI, etc. However, there are always plusses and minuses so I thought I would ask for some community input.
Here are some rough requirements:
The format is a "standard"...I don't want to reinvent the wheel if I don't have to. It doesn't have to be a formal IEEE standard, but something you could Google and get some information on as a new user, may have some support tools (editors) beyond vi. (Though the software users will generally be computer savvy and happy to use vi.)
Easily integrates with C++. I don't want to have to pull along a 100mb library and three different compilers to get it up and running.
Supports tabular input (2d, n-dimensional)
Supports POD types
Can expand as more inputs are required, binds well to variables, etc.
Parsing speed is not terribly important
Ideally, as easy to write (reflect) as it is to read
Works well on Windows and Linux
Supports compositing (one file referencing another file to read, and so on.)
Human Readable
In a perfect world, I would use a header-only library or some clean STL implementation, but I'm fine with leveraging Boost or some small external library if it works well.
So, what are your thoughts on various formats? Drawbacks? Advantages?
Edit
Options to consider? Anything else to add?
XML
YAML
SQLite
Google Protocol Buffers
Boost Serialization
INI
JSON
There is one excellent format that meets all your criteria:
SQLite!
Please read article about using SQLite as an application file format. Also, please watch Google Tech Talk by D. Richard Hipp (SQLite author) about this very topic.
Now, lets see how SQLite meets your requirements:
The format is a "standard"
SQLite has become format of choice for most mobile environments, and for many desktop apps (Firefox, Thunderbird, Google Chrome, Adobe Reader, you name it).
Easily integrates with C++
SQLite has standard C interface, which is only one source file and one header file. There are C++ wrappers too.
Supports tabular input (2d, n-dimensional)
SQLite table is as tabular as you could possibly imagine. To represent say 3-dimensional data, create table with columns x,y,z,value and store your data as a set of rows like this:
x1,y1,z1,value1
x2,y2,z2,value2
...
Supports POD types
I assume by POD you meant Plain Old Data, or BLOB. SQLite lets you store BLOB fields as is.
Can expand as more inputs are required, binds well to variables
This is where it really shines.
Parsing speed is not terribly important
But SQLite speed is superb. In fact, parsing is basically transparent.
Ideally, as easy to write (reflect) as it is to read
Just use INSERT to write and SELECT to read - what could be easier?
Works well on Windows and Linux
You bet, and all other platforms as well.
Supports compositing (one file referencing another file to read)
You can ATTACH one database to another.
Human Readable
Not in binary, but there are many excellent SQLite browsers/editors out there. I like SQLite Expert Personal on Windows and sqliteman on Linux. There is also SQLite editor plugin for Firefox.
There are other advantages that SQLite gives you for free:
Data is indexable which makes it very fast to search. You just cannot do this using XML, JSON or any other text-only formats.
Data can be edited partially, even when amount of data is very large. You do not have to rewrite few gigabytes just to edit one value.
SQLite is fully transactional: it guarantees that your data is consistent at all times. Even if your application (or whole computer) crashes, your data will be automatically restored to last known consistent state on next first attempt to connect to the database.
SQLite stores your data verbatim: you do not need to worry about escaping junk characters in your data (including zero bytes embedded in your strings) - simply always use prepared statements, that's all it takes to make it transparent. This can be big and annoying problem when dealing with text data formats, XML in particular.
SQLite stores all strings in Unicode: UTF-8 (default) or UTF-16. In other words, you do not need to worry about text encodings or international support for your data format.
SQLite allows you to process data in small chunks (row by row in fact), thus it works well in low memory conditions. This can be a problem for any text based formats, because often they need to load all text into memory to parse it. Granted, there are few efficient stream-based XML parsers out there, but in general any XML parser will be quite memory greedy compared to SQLite.
Having worked quite a bit with both XML and json, here's my rather subjective opinion of both as extendable serialization formats:
The format is a "standard": Yes for both
Easily integrates with C++: Yes for both. In each case you'll probably wind up with some kind of library to handle it. On Linux, libxml2 is a standard, and libxml++ is a C++ wrapper for it; you should be able to get both of those from your distro's package manager. It will take some small effort to get those working on Windows. There appears to be some support in Boost for json, but I haven't used it; I've always dealt with json using libraries. Really, the library route is not very onerous for either.
Supports tabular input (2d, n-dimensional): Yes for both
Supports POD types: Yes for both
Can expand as more inputs are required: Yes for both - that's one big advantage to both of them.
Binds well to variables: If what you mean is some way inside the file itself to say "This piece of data must be automatically deserialized into this variable in my program", then no for both.
As easy to write (reflect) as it is to read: Depends on the library you use, but in my experience yes for both. (You can actually do a tolerable job of writing json using printf().)
Works well on Windows and Linux: Yes for both, and ditto Mac OS X for that matter.
Supports one file referencing another file to read: If you mean something akin to a C #include, then XML has some ability to do this (e.g. document entities), while json doesn't.
Human readable: Both are typically written in UTF-8, and permit line breaks and indentation, and thus can be human-readable. However, I've just been working with a 479 KB XML file that's all on one line, so I had to run it through a prettyprinter to make sense of it. json can also be pretty unreadable, but in my experience is often formatted better than XML.
When starting new projects, I generally prefer json; it's more compact and more human-readable. The main reason I might select XML over json would be if I were worried about receiving badly-formed documents, since XML supports automated document format validation, while you have to write your own validation code with json.
Check out google buffers. This handles most of your requirements.
From their documentation, the high level steps are:
Define message formats in a .proto file.
Use the protocol buffer compiler.
Use the C++ protocol buffer API to write and read messages.
For my purposes, I think the way to go is XML.
The format is a standard, but allows for modification and flexibility for the schema to change as the program requirements evolve.
There are several library options. Some are larger (Xerces-C) some are smaller (ezxml), but there are many options, so we won't be locked in to a single provider or very specific solution.
It can supports tabular input (2d, n-dimensional). This requires more parsing work on "our" end, and is likely the weakest point for XML.
Supports POD types: Absolutely.
Can expand as more inputs are required, binds well to variables, etc. through schema modifications and parser modifications.
Parsing speed is not terribly important, so processing a text file or files is not an issue.
XML can be programmatically written just as easily as read.
Works well on Windows and Linux or any other OS that supports C and text files.
Supports compositing (one file referencing another file to read, and so on.)
Human Readable with many text editors (Sublime, vi, etc.) supporting syntax highlighting out of the box. Many web browsers display the data well.
Thanks for all the great feedback! I think if we wanted a purely binary solution, Protocol Buffers or boost::serialization is likely the way that we would go.
We have a proprietary file format which has embedded in it a product-code.
I am just starting down the path of "enabling the end-user to sort / filter by product-code when opening a file".
The simplest approach for us might be to simply have another drop-down in our customized Open File Dialog in which to choose a product-code to filter by.
However, I think it might be more useful to the end-user if we could present this information as a column in the details view for this file type - just as name, date-modified, type, size, etc., are also detail properties of a file-type (or perhaps generic to all files).
My vague understanding is that XP and prior Windows OSes embedded some sort of meta data like this in an alternate data stream in NTFS. However, Starting in Vista Microsoft stopped using alternate data streams due to their dependence upon NTFS, and hence fragility (i.e. can't send via file attachment, can't move to a FAT formatted thumb drive, etc.)
Things I need to know but haven't figured out yet:
Is it possible / Is it practicable / how to create a custom extended file property for our file type that expresses the product-code to the Windows shell so that it can be seen in Windows Explorer (and hence File dialogs)?
If that is doable, then how to configure things so that the product-code column is displayed by default for folders containing our file type.
Can anyone point me to a good starting point on the above? We certainly don't have to accomplish this by publishing a custom extended file property - but that seems like a sensible approach, in absence of any way to measure the costs of going this route.
If you have sensible alternative approaches to the problem, I'd be interested in those as well!
Just found: http://www.codeproject.com/Articles/830/The-Complete-Idiot-s-Guide-to-Writing-Shell-Extens
CRAP! It seems I'm very late to the banquet, and MS has already removed this functionality from their shell: http://xpwasmyidea.blogspot.com/2009/10/evil-conspiracy-behind-customizable.html
By far the easiest approach to developing a shell extension is to use a library made for the purpose.
I can recommend EZShellExtension because I have used it in the past to add columns and thumbnails/preview for a custom file format for our company.
I like to print a document. The content of the document are tables and text with different colors. Does a lightwight printer-file-format exist, which can be used like a template?
PS, PDF, DOC files in my opinion are to heavy to parse. May there exist some XML or YAML file format which supports:
Easy creation (maybe with a WYSIWYG-Editor)
Parsing and manipulation with Library-Support
Easy sending to the printer (maybe with Library-Support)
Or do I have to do it the usual way and paint within a CDC?
I noticed you’re using MFC (so, Windows). In that case the answer is a qualified yes. In recent versions of Windows, Microsoft offers the XPS Document API which lets you create and manipulate a PDF-like document using XML, which can then be printed using the XPS Print API.
(For earlier versions of Windows that don’t support this API, you could try to deal with the XPS file format directly, but that is probably a lot harder than using CDC. Even with the API you will be working at a fairly low level.)
End users can generate XPS documents using the XPS print driver that is available for free from Microsoft (and bundled with certain MS products—they probably already have it on their system).
There is no universal language that is supported across all (or even many) printers. While PCL and PS are the most used, there are also printers which only work with specific printer drivers because they only support a proprietary data format (often pre-rendered on the client).
However, you could use XSL-FO to create documents which can then be rendered to a printer driver using library support.
I think something like TeX or LaTeX (or even troff or groff) may meet your needs. Google them and see.
There are also libraries to render documents for print from HTML source. Look at http://libharu.sourceforge.net/ for example. This outputs a printer-ready .PDF
A think that Post Script is a really good choice for that.
It is actually a very simple language, and it must be very easy to parse becuse it is stack-oriented. Then -- most printers supprort it, and even if you have no support you can use GhostScript to convert for many different formats (Consider GS as a "virtual PS supporting printer").
Finally there are a lot of books and tutorials for the language.
About the parsing -- you can actually define new variables and functions in PS. So, maybe, your problem can be solved (almost) entirely using PS.
HTML + CSS can be printed -- properly. CSS was designed to support this with the media attribute to specify that your CSS is for printer layout, not for screen layout. Tools like PRINCE (free + commercial versions) exist to render this for printing.
I think postscript is the markup language used by printers. I read this somewhere, so correct me if postscript is now outdated.
http://en.wikipedia.org/wiki/PostScript
For more powerful suite you can use Latex. It will give options of creating templates where you can just copy the text.
On a more GUI friendly note, MS-Word and other word processors have templates. The issue is they are not of a common standard or markup.
You can also use HTML to render stuff in a common markup but it will not be very printer friendly.
I've been tasked with creating a tool that can diff and merge the configuration files for my company's product. The configurations are stored as either XML or URL-encoded strings. I'm looking for a library, preferably open source with a license compatible with commercial software, that can do these diffs. Our app is written in C++, so C++ libraries would be best, but I'm willing to look at libraries that are C#-specific since I can write a wrapper that exposes it to C++ via COM. Three-way diffs would be ideal, but two-way is acceptable. If it has an understanding of XML, that would also be a plus (since XML nodes can be reordered without changing the document, etc). Any library suggestions? Should I even consider writing my own diff tools in the hopes of giving it semantic knowledge of our formats?
Thanks to this similar question, I've already discovered this google library, which seems really great, but I'm still looking for other options. It also seems to be able to output the diffs in HTML format (using the <ins> and <del> tags that I didn't know existed before I discovered it), which could be really handy, but it seems to be a unified diff only. I'm going to need to display the results in a web browser, and probably have to build an interface for doing the merges in the browser as well. I don't expect a library to be able to help with these tasks, but it must produce output in a format that is amenable to me building this on top of it. I'm currently envisioning something along the lines of TortoiseMerge (side-by-side diffs, not unified), except browser-based. Any tips/tricks/design ideas on how to present this would be appreciated too.
Subversion comes with libsvn_diff and libsvn_delta licensed under Apache Software License.
Here is a C++ library that can diff what the author calls semistructured data. It deals nicely with HTML and XML. Since your data is XML it would make a lot of sense to use this instead of plain text diff. This is especially the case when the files are machine generated.
I am currently trying to use this library to build a tool that diffs Visual Studio project files. These are basically XML files and using a plain diff tool like Winmerge is too painful because Visual Studio pretty much mucks up the whole file by crazy reordering. The idea is to do some kind of a structured diff to address the problem.
For diffing the XML I would propose that you normalize it first: sort all the elements in alphabetic order, then generate a stream of tokens/xml that represents the original document but is independent of the original formatting. After running the diff, parse the result to get a tree containing what was added / removed.